Compensation for attenuation of carrier power by a transmission path

ABSTRACT

A system and method for compensating for attenuation of carrier power by a transmission path. The method includes defining a path from a gateway to a measurement tap, where the path may include an output port of the gateway and path components used to reach the measurement tap; sweeping, in bands, an RF spectrum served by the RFT by sending a signal at a respective band and a band power from the output port over the path; measuring, at the measurement tap, a power metric for each of the bands; capturing, for each of the bands, power level (PL) data including a frequency start of the respective band, a frequency end of the respective band, the respective band power and the respective power metric at the measurement tap; and setting a carrier power level (CPL) of a carrier having a frequency start and a frequency end, where the CPL is based on the PL data associated with one more of the bands included in the frequency start and the frequency end, where the path components may include one or more connecting cables, one or more switches, and one or more equipment in the path.

CROSS-REFERENCE TO RELATED APPLICATIONS AND INCORPORATION BY REFERENCE

The present application is a continuation of U.S. Non-Provisionalapplication Ser. No. 17/363,316 filed Jun. 30, 2021, and claims thebenefit under 35 U.S.C. 119(e) of U.S. Provisional Application Ser. No.63/134,652, filed Jan. 7, 2021, which are incorporated herein byreference in their entireties.

FIELD

The present teachings compensate for attenuations and non-linearities ofcarrier power by a transmission path used in a communication system. Amethod and system to dynamically set an appropriate carrier power atruntime to compensate for the attenuations and non-linearities.Necessary compensation may be determined via a calibration exercise tocapture relevant information.

BACKGROUND

Prior to the present teachings, the process of setting transmit powerfor individual carriers was manual. In a communication system that usesdifferent carriers, power levels have to be adjusted and tuned toaccount for varying attenuation in a transmission path the adjustmentsare typically done manually. The attenuation may be due to non-linearcharacteristics of the path specific attenuation. In a satellite-basedcommunication system, this could be due to non-linear Radio FrequencyTransmitter (RFT) flatness. In any communication system, this could alsobe due to the carrier taking a different transmission path due toredundancy available for different components in the path—including, butnot limited to different cables, switches, splitters, wave guides etc.

In existing systems, the carrier power setting is a manual task everytime any component in the transmission path changes, or every time anycarrier is modified. Components in the path can be, but not limited to,modulators, cables, switches, splitters, wave guides etc. In operationalsystems, carrier measurement data from installed test or customerterminal base is gathered over a couple of days of period to fine tunethe carrier power further.

SUMMARY OF THE INVENTION

This Summary is provided to introduce a selection of concepts in asimplified form that is further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

Any, satellite based or other, communication system that requiresmultiple carriers and needs to adjust a transmit power of those carriersto account for possible variations over time may use the presentteachings. The adjustment to a transmit power may be due to carrierchanges or component changes in the transmission path. The improvementsand benefits of using an Automatic Carrier Power Setting (ACPS) in thesystem are:

-   -   Network operators or RF engineers need not perform carrier        balancing or carrier setting exercise after each carrier plan        change.    -   ACPS allows for automatic carrier changes in a system where        carriers can be reconfigured programmatically.

A system of one or more computers can be configured to performparticular operations or actions by virtue of having software, firmware,hardware, or a combination of them installed on the system that inoperation causes or cause the system to perform the actions. One or morecomputer programs can be configured to perform particular operations oractions by virtue of including instructions that, when executed by dataprocessing apparatus, cause the apparatus to perform the actions. Onegeneral aspect includes a method for compensating for attenuation ofcarrier power by a transmission path. The method includes defining apath from a gateway to a measurement tap, where the path may include anoutput port of the gateway and path components used to reach themeasurement tap; sweeping, in bands, an RF spectrum served by the RFT bysending a signal at a respective band and a band power from the outputport over the path; measuring, at the measurement tap, a power metricfor each of the bands; capturing, for each of the bands, power level(PL) data including a frequency start of the respective band, afrequency end of the respective band, the respective band power and therespective power metric at the measurement tap; and setting a carrierpower level (CPL) of a carrier having a frequency start and a frequencyend, where the CPL is based on the PL data associated with one more ofthe bands included in the frequency start and the frequency end, wherethe path components may include one or more connecting cables, one ormore switches, and one or more equipment in the path. Other embodimentsof this aspect include corresponding computer systems, apparatus, andcomputer programs recorded on one or more computer storage devices, eachconfigured to perform the actions of the methods.

Implementations may include one or more of the following features. Themethod where the band power of each of the bands is same and a frequencyrange of each of the bands is same. The measurement tap may include anantenna flange of the RFT. The path may include a satellite. Themeasurement tap may be disposed along an uplink from the RFT to asatellite. The measurement tap may include an antenna flange of areceiver antenna. The method may include changing the path components;and updating the PL data and the CPL to reflect the changing. Thecarrier may include a plurality of carriers, and for each of thecarriers the CPL is computed. The setting may include computing the CPLbased on an area under a curve of the PL data from the frequency startto the frequency end. The method further may include transmitting overthe path by varying a desired power level of the carrier at themeasurement tap based on the CPL. Implementations of the describedtechniques may include hardware, a method or process, or computersoftware on a computer-accessible medium.

One general aspect includes a system to compensate for attenuation ofcarrier power by a transmission path. The system includes a path from agateway to a measurement tap, where the path may include an output portof the gateway and path components used to reach the measurement tap; apower level module to sweep, in bands, an RF spectrum served by the RFTby sending a signal at a respective band and a band power from theoutput port over the path, to capture, for each of the bands, powerlevel (PL) data including a frequency start of the respective band, afrequency end of the respective band, the respective band power and arespective power metric at the measurement tap; and to set a carrierpower level (CPL) of a carrier having a frequency start and a frequencyend. The system also includes a measurement module to measure, at themeasurement tap, the power metric for each of the bands; where the CPLis based on the PL data associated with one more of the bands includedin the frequency start and the frequency end, where the path componentsmay include one or more connecting cables, one or more switches, and oneor more equipment in the path. Other embodiments of this aspect includecorresponding computer systems, apparatus, and computer programsrecorded on one or more computer storage devices, each configured toperform the actions of the methods. Additional features will be setforth in the description that follows, and in part will be apparent fromthe description, or may be learned by practice of what is described.

DRAWINGS

In order to describe the manner in which the above-recited and otheradvantages and features may be obtained, a more particular descriptionis provided below and will be rendered by reference to specificembodiments thereof which are illustrated in the appended drawings.Understanding that these drawings depict only typical embodiments andare not, therefore, to be limiting of its scope, implementations will bedescribed and explained with additional specificity and detail with theaccompanying drawings.

FIG. 1A illustrates a transmission path up to an RFT according tovarious embodiments.

FIG. 1B illustrates a transmission path including a satellite and a UEaccording to various embodiments.

FIG. 2 illustrates calibration result data for multiple paths accordingto various embodiments.

FIG. 3 illustrates a method for compensating for attenuation of carrierpower by a transmission path according to various embodiments.

Throughout the drawings and the detailed description, unless otherwisedescribed, the same drawing reference numerals will be understood torefer to the same elements, features, and structures. The relative sizeand depiction of these elements may be exaggerated for clarity,illustration, and convenience.

DETAILED DESCRIPTION

The present teachings may be a system, a method, and/or a computerprogram product at any possible technical detail level of integration.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as SMALLTALK, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general-purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

Reference in the specification to “one embodiment” or “an embodiment” ofthe present invention, as well as other variations thereof, means that afeature, structure, characteristic, and so forth described in connectionwith the embodiment is included in at least one embodiment of thepresent invention. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment”, as well any other variations,appearing in various places throughout the specification are notnecessarily all referring to the same embodiment.

Introduction

The present teachings set carrier power automatically to account for RFTflatness and other variability of signal attenuation over differenttransmission paths based on calibration data. The calibration data maybe collected and captured at a commissioning of a gateway, a RadioFrequency Transmitter (RFT) equipment at the gateway, or a component ina Tx path.

-   -   Gateway: Location that has RF link to the satellite to transmit        and receive data from terminals and that has terrestrial or        other connectivity to be able to link the terminals to the        internet.    -   RFT: Radio Frequency Transmitter for the Gateway.    -   Terminal/VSAT: End-user Very Small Aperture Terminal, End-user        satellite antenna and modem.

Transmission Path Up to an RFT

FIG. 1A illustrates a transmission path up to an RFT according tovarious embodiments.

A satellite communication system 100 may include a Gateway 102, Tx pathcomponents 104 and an RFT 106. The Tx path components 104 connect anoutput port 110 of the gateway 102 with the RFT 106. The Tx pathcomponents 104 may include cables, switches and other Tx components. Inthe system 100, the measurements of the measurement module may be usedto vary power at the output port 110 of the gateway 102 for a given pathand carrier to achieve a desired output power at a measurement tap per aLink Budget calculation.

An output power metric may be measured with a measurement module 114 ata measurement tap. The output power metric may be captured in the formof Carrier Power Level (CPL), path attenuation, RFT output power or anyother related measurement that is usable to derive the power at theoutput port 110 of the gateway 102 for a given path and carrier. In someembodiments, there can be multiple/redundant paths to a measurement tapdifferentiated by one or more of the output port 110, the Tx pathcomponents 104 or combinations thereof. In some embodiments, a gateway102 may have multiple output ports 110. Components of the system 100defining each of the multiple paths may be represented as a unit.

The path 112 may be defined based on a selection of a measurement tap.The measurement tap may be at an antenna flange of the RFT 106. As such,the path 112 includes the output port 110, the Tx path components 104and the measurement tap (antenna flange of the RFT 106). For example,the path 112 may include an output port 110, Tx path components 104(including connecting cables, switches, any other equipment in the path)up to a Traveling-wave tube amplifier (TWTA) connecting to the RFT 106antenna flange.

In some embodiments, the measurement tap may be disposed along a travelpath of uplink 118 radiated from the RFT 106. The path 112 may bedefined as the output port 110, the Tx path components 104, the RFT 106and the uplink 118 measurement tap.

In order to obtain power level data 116 based on measured data alongeach path in the system 100, a power level module 120 at the gateway 102may help output a carrier of desired size based on a granularity offrequency bands for which measurements are needed. At the desiredgranularity of frequency bands for a carrier size, the gateway 102 maysweep an entire Radio Frequency (RF) spectrum that the RFT 106 canserve. In some embodiments, a Carrier Power Level (CPL) for eachmeasurement of each of the multiple paths may be computed and stored aspower level data 116 by the power level module 120. The multiple pathsmay provide different redundancy paths while in operation andmeasurements for each of the multiple paths may be noted as calibrationresults. The power level module 120 may receive the power metrics fromthe measurement module 114.

Transmission Path Up to a User Equipment

In some embodiments, a satellite may support adjustment and tuning ofcarrier power to account for non-linearity caused due to satellitetransponders. Some satellite systems lack that capability.

FIG. 1B illustrates a transmission path including a satellite and a UEaccording to various embodiments.

A satellite communication system 150 may include a Gateway 102, Tx pathcomponents 104 and a RFT 106. A path 152 may connect the output port 110of the gateway 102 with a receiver antenna 154. The path 152 may includethe output port 110, the Tx path components 104, the RFT 106, the uplink118, the satellite 108, a downlink 160 and an antenna flange of thereceiver antenna 154. In such embodiments, the antenna flange of thereceiver antenna 154 as the measurement tap for the path 152. Componentsof the path 152 included in defining the path 152 may be represented asa unit. The Tx path components 104 may include cables, switches andother Tx components. In some embodiments, there can be multiple,possibly redundant, paths to connect the gateway 102 to the receiverantenna 154. The receiver antenna 154 may be installed and enabled indifferent spotbeams or shaped beams to perform a local measurement witha measurement module 156 for the path 152.

In some embodiments of the system 150, a measurement tap may be desiredat an input port UE 158. In some embodiments of the system 150, ameasurement tap may be desired along a downlink 160.

In some embodiments, the local measurements may be sent back to thegateway 102 via satellite communications, terrestrial communications, orthe like. A proper Carrier Power Level (CPL) at different frequenciesmay be stored as power level data 116 for each of the multiple paths 152based on the local measurement made with the measurement module 156.

Measurement

The present teachings may record measurements for a carrier size basedon granularity of measurements needed. Using larger carrier sizesresults in fewer measurements but may hide non-linearities within afrequency range of the carrier. Using smaller carrier sizes duringcalibration process results in a larger dataset that may capture finernon-linearities of the attenuations in the path.

FIG. 2 illustrates calibration result data for multiple paths accordingto various embodiments.

FIG. 2 illustrates a CPL measurement as a plot illustrating:

-   -   RFT Input (MHz)    -   Redundancy Path Identifier    -   dBm/kHz or dBm/MHz gateway output power as measured at a        measurement tap

In FIG. 2 , the dBm/kHz or dBm/MHz gateway output power is shown on avertical axis for paths 1-6 (depths axis) for an RFT frequency spectrum,here 950 MHz to 2400 MHz (horizontal axis). The illustration may becaptured as a configuration in a convenient format, for example, a list,a table in a database, csv, j son, XML or the like. The granularity ofthe frequency bands, Tx or Rx, in the configuration may beimplementation specific. The granularity may be uniformly stepped, forexample, 25, 40, 50, 75 MHz or the like. The granularity stepping neednot be uniform. For example, a frequency band of a first granularity mayspan 50 MHz and a second different and non-overlapping granularity mayhave a frequency band that spans 100 MHz. The frequency spectrum of acarrier or an RFT frequency spectrum may be non-contiguous.

In this specific example, gateway output power as measured at ameasurement tap, for example, at an antenna flange of the RFT, along anuplink, along a downlink, an antenna flange of a receiver antenna, a UEinput port, or the like. The metric measured at the measurement tap maybe captured in the form of path attenuation, RFT output power or anyother related measurement that can be used to derive required gatewaytransmit power for a frequency band.

For ease of measurement, a measurement may be performed by varying theRFT Input by sweeping a carrier of a desired band/granularity from startto end of an RFT's supported spectrum. The carrier power may be keptconstant during the sweep. A deviation from desired power at themeasurement tap, for example, the input of antenna flange at the RFT, ata UE or the like can be measured. A pretty good estimate of requiredtransmit powers at the gateway may be obtained after a sweep. Subsequentsweeps may be used to get more accurate results that, for example,correct for measurement difference during a previous sweep, for example,the immediately preceding sweep.

Use of Power Level Data

After selecting a path and a frequency range, a gateway component mayadjust the transmit power per the power level data. In some embodiments,a gateway may compute required carrier power based on size and locationof the carrier on RF spectrum. Carrier power may be computed as an areaunder the curve for a given path the carrier is to take between thestart and the end frequency of the carrier. A desired power level of aTx carrier at a measurement tap may be provided by a link budget table.

FIG. 3 illustrates a method for compensating for attenuation of carrierpower by a transmission path according to various embodiments.

A method 300 for compensating for attenuation of carrier power by atransmission path may include an operation 302 to define a path from agateway to a measurement tap. The method 300 may include an operation304 to sweep an RF spectrum by sending a signal at a respective band anda band power from the output port over the path. The method 300 mayinclude an operation 306 to measure, at the measurement tap, a powermetric for each of the bands. The method 300 may include an operation308 to capture, for each of the bands, PL data including the respectivepower metric at the measurement tap. The method 300 may include anoperation 310 to set a CPL of a carrier having a frequency start and afrequency end based on the PL data associated with one more of the bandsincluded in the carrier. The method 300 may include an operation 312 tocompute the CPL based on an area under a curve of the PL data from thefrequency start to the frequency end. The method 300 may include anoperation 314 to transmit over the path by varying a desired power levelof the carrier based on the CPL. The method 300 may include an operation316 to change the path components. The method 300 may include anoperation 318 to update the PL data and the CPL.

Having described preferred embodiments of a system and method (which areintended to be illustrative and not limiting), it is noted thatmodifications and variations can be made by persons skilled in the artconsidering the above teachings. It is therefore to be understood thatchanges may be made in the embodiments disclosed which are within thescope of the invention as outlined by the appended claims. Having thusdescribed aspects of the invention, with the details and particularityrequired by the patent laws, what is claimed and desired protected byLetters Patent is set forth in the appended claims.

I claim:
 1. A method for setting carrier power for bands of an RF spectrum, the method comprising; defining a path from an output port to a measurement tap via path components to connect to the measurement tap; sending, for the bands, a signal at a respective band and a band power from the output port over the path; measuring, at the measurement tap, a power metric of the signal for each of the bands; capturing, for each of the bands, Power Level (PL) data for the path comprising a frequency start of the respective band, a frequency end of the respective band, the respective band power and the respective power metric at the measurement tap; and setting a Carrier Power Level (CPL) of a carrier to be transmitted over the path, wherein the carrier comprises one or more of the bands and the CPL is based on the PL data associated with the one or more of the bands, wherein the path components comprise one or more equipment in the path.
 2. The method of claim 1, wherein the path comprises one or more connecting cables and one or more switches.
 3. The method of claim 1, wherein the sending uses a same level for the band power of each of the bands.
 4. The method of claim 1, wherein one of the bands has a first granularity of frequency range, another of the bands has a second granularity of frequency range and the first granularity is different than the second granularity.
 5. The method of claim 1, wherein the PL data comprises a path attenuation, an output power at the measurement tap of the band power during the sending.
 6. The method of claim 1, further comprising transmitting over the path by varying the carrier power based on the CPL.
 7. The method of claim 1, wherein the measurement tap comprises an antenna flange of a Radio Frequency Transmitter (RFT) and the output port comprises a gateway output port.
 8. The method of claim 1, wherein the measurement tap is disposed along an uplink from an RFT to a satellite.
 9. The method of claim 1, wherein the measurement tap comprises an antenna flange of a receiver antenna.
 10. The method of claim 1, further comprising changing the path components; and updating the PL data and the CPL to reflect the changing.
 11. The method of claim 1, wherein the carrier comprises a plurality of carriers, and for each of the carriers the CPL is computed.
 12. The method of claim 1, wherein the setting comprises computing the CPL based on an area under a curve of the PL data from the frequency start to the frequency end.
 13. A system to set carrier power for bands of an RF spectrum, the system comprising; a path from an output port to a measurement tap via path components to connect to the measurement tap; a power level module to send, for the bands, a signal at a respective band and a band power from the output port over the path, to capture, for each of the bands, Power Level (PL) data for the path comprising a frequency start of the respective band, a frequency end of the respective band, the respective band power and a respective power metric at the measurement tap, and to set a Carrier Power Level (CPL) of a carrier of a carrier to be transmitted over the path, wherein the carrier comprises one or more of the bands and the CPL is based on the PL data associated with the one or more of the bands; and a measurement module to measure, at the measurement tap, the power metric for each of the bands, wherein the path components comprise one or more equipment in the path.
 14. The system of claim 13, wherein the path comprises one or more connecting cables and one or more switches.
 15. The system of claim 13, wherein one of the bands has a first granularity of frequency range, another of the bands has a second granularity of frequency range and the first granularity is different than the second granularity.
 16. The system of claim 13, wherein the measurement tap is disposed along an uplink from an RFT to a satellite and the output port comprises a gateway output port.
 17. The system of claim 13, wherein the power level module is configured to change the path components and to update the PL data and the CPL to reflect the changing.
 18. The system of claim 13, wherein the carrier comprises a plurality of carriers, and for each of the carriers the CPL is computed.
 19. The system of claim 13, wherein the power level module computes the CPL based on an area under a curve of the PL data from the frequency start to the frequency end.
 20. The system of claim 13, wherein the power level module varies the carrier power based on the CPL for the path. 